A method of this type is known from experience. In this context Hall sensors—whose measuring signals are utilized on the one hand for the electronic commutation of the coil of the EC motor and on the other hand also for the measurement of the absolute position that the secondary part has relative to the primary part—are used as magnetic field sensors. As a result it is possible to do without an additional absolute value sensor. For determination of the absolute position, a reference position having a known absolute position is first approached. The reference position may, for example, be a limit stop against which the secondary part is positioned during a reference run. At the reference position, the absolute position value is set to the corresponding reference position value, which may have, for example, the value zero. Thereafter, the EC motor is electronically commutated in order to position the secondary part according to a setpoint signal of a higher order control or regulation device than the primary part, the absolute position value being tracked every time there is a change of the measured value combination. However, errors in the tracking of the absolute position value may occur in practice, for example, if the measuring signals of the magnetic field sensors are distorted by EMC (electromagnetic) irradiation. If the absolute position signal is incorrectly tracked due to an interference of this type, all additional absolute position values are shifted relative to the actual position. Therefore, electric motors that are mechanically commutated via brushes and equipped with an absolute position sensor have been used heretofore for applications in which a danger may be posed by an incorrect positioning of the secondary part relative to the primary part, such as in an electric motor for the automated actuation of a clutch disposed between a combustion engine and a mechanical manual transmission in a motor vehicle and/or in an electric motor for adjusting a shifting shaft in an automatic transmission of a motor vehicle. With an absolute value sensor of this type, the absolute position of the electric motor may be determined even after a reset of the electronic controller of the clutch or of the manual transmission without a reference run being necessary. Therefore, such a reset may occur largely unnoticed by the user of the motor vehicle, even during the operation of the motor vehicle, for example, if the power supply of the motor vehicle was temporarily disrupted or failed briefly because of a defect. However, absolute position sensors of this type are relatively expensive and extravagant.